Comparación de caracteres merísticos y morfométricos entre peces del género Sicyases del archipiélago de Juan Fernández, Valparaíso y Valdivia (Osteichthyes: Gobiesocidae)

Abstract

The clingfishes of the genus Sicyases (Müller y Troschel, 1843), are located in the continent?s coast and also in the Juan Fernandez archipelago (33º41?S, 79º47?W aprox). They externally look alike, therefore, it is hard to see the differences and there are even doubts from being different species. Meristical and morfometrical characteristics were studied for the A. Selkirk and R. Crusoe islands (both from the Juan Fernandez archipelago), coast of Valparaíso and Valdivia. The clingfishes were all compared to establish which are the species of Sicyases living in Chile. Frequency analysis of meristical characteristics, triangle graphics and analysis of mean differences, including in the last case the amplitude (range) and standard deviation for morfometrical characteristics were studied. Qualitative and quantitative differences were found between the samples of the islands and the continent in reference to the number of anal fin rays, the head?s length, maximum body width, posterior suck margin width and the skin?s texture (smooth or wrinkled). The results ratify the existence of two species; Sicyases hildebrandi (Schultz, 1944) in the Juan Fernandez archipelago and S. sanguineus (Müller and Troschel, 1843) in the continental coastline of Chile. The specimens from Valdivia showed an overlapped patron, compared to insular specimens and as well as those from Valparaíso; however because they are from the continental coastline are supposedly in a geographical continuity and hence, must belong to the same species, Sicyases sanguineus. The new set of characteristics and the geographic isolation supports the redefinition of S. hildebrandi as the only species of the genus in Juan Fernandez archipelago and a new taxonomic key to recognize the species is presented